1. Technical Field
The present invention relates to a high-efficiency AlGaInP light-emitting diode directly grown on a transparent substrate and a method of manufacturing the same, and, more particularly, to a high-efficiency AlGaInP light-emitting diode grown on a sapphire substrate and a method of manufacturing the same.
2. Description of the Related Art
An AlGaInP light-emitting diode is used as a high-brightness light-emitting diode in a visible light region of 550˜670 nm. The efficiency of an AlGaInP light-emitting diode with a GaAs substrate is very low because most of light emitted downward from diode was absorbed by the GaAs substrate.
Thus, an AS-LED (Absorbing Substrate LED) in which a DBR (distribution Bragg reflector) is provided on a GaAs substrate to reflect part of light emitted from the diode to the substrate was developed. However, this AS-LED is problematic in that the DBR is fabricated by a complicated procedure and light is reflected only at a predetermined angle.
Further, a method of manufacturing a light-emitting diode (LED) by removing a GaAs substrate using etching and then attaching a visible-light transmittable GaP substrate to the LED using wafer bonding was developed. However, this method is problematic in that an ESL (Etching Stop Layer) is needed in order to selectively etch a GaAs substrate and in that an LED is damaged by pressing during a wafer bonding procedure, thus increasing a defective fraction. Further, this method has a problem that a GaP substrate is expensive and thus economically inefficient.